Numerous biotechnological processes make use of genetically engineered organisms in order to produce bulk or fine chemicals, proteins or antibiotics. In many cases, increased production has been obtained by improved gene expression and by optimization of growth conditions. In all processes we are aware of, the initial carbon-precursor has been and still is sugar (notably glucose, but many other mono- and polysaccharides are in use) or related organic substrates: solventogenesis (including butanol and ethanol) and organic acid production (e.g. lactic-, citric- or succinic acid) always starts from glucose, which makes it inefficient as the production process uses a high energy initial compound as substrate.
Lactic acid is a naturally occurring organic acid, which has many applications, e.g. it can be used as an acidulant, preservative in the food industry, pharmaceutical, leather and textile industries, as well as a chemical feedstock (Vijayakumar et al. (2008) Chem. Biochem. Eng. Q 22(2):245-264).
Lactic acid can be produced either via chemical synthesis or via microbial fermentation. Currently, most of the lactic acid is producted via microbial fermentation using lactic acid bacteria, although production using filamentous fungi is also known (Vijayakumar et al. vide supra).
However, there is still a need for an alternative and even improved production process of L-lactate, preferably without the need of expensive or complicated starting materials, which process does not have the drawbacks of existing processes.